libgodc

Welcome to libgodc — a minimal Go runtime implementation for the Sega Dreamcast.

This project brings the Go programming language to a 1998 game console with 16MB of RAM, a 200MHz SH4 processor, and absolutely no operating system to speak of. It’s an exercise in constraints, a love letter to retro hardware, and a deep dive into how programming languages actually work under the hood.

What is libgodc?

libgodc replaces the standard Go runtime (libgo) with one designed for the Dreamcast’s unique constraints:

Despite these differences, you write normal Go code. Goroutines work. Channels work. Maps, slices, interfaces — they all work. The magic is in the runtime.

Who is this for?

• Systems programmers curious about runtime implementation
• Go developers who want to understand what happens below go run
• Retro enthusiasts who think game consoles deserve modern languages
• Anyone who enjoys the challenge of severe constraints

Prerequisites

Before diving in, you should be comfortable with:

You don’t need to know:

• Assembly language (we’ll explain what you need)
• Dreamcast hardware (KallistiOS handles the hard parts)
• Garbage collection algorithms (we’ll build one together)
• Operating system internals (we’ll cover what’s relevant)

If you can write a Go program that uses goroutines and channels, and you know what a pointer is in C, you’re ready.

What’s in this book?

Getting Started

Installation, toolchain setup, and your first Dreamcast Go program.

The Book

A complete walkthrough of building a Go runtime from scratch:

• Memory allocation and garbage collection
• Goroutine scheduling without threads
• Channel implementation
• Panic, defer, and recover
• Building real games

Reference

Technical documentation for daily use:

• API design
• Best practices
• Hardware integration
• Known limitations

Quick Example

package main

import "kos"

func main() {
    kos.PvrInitDefaults()
    
    for {
        kos.PvrWaitReady()
        kos.PvrSceneBegin()
        kos.PvrListBegin(kos.PVR_LIST_OP_POLY)
        // draw stuff here
        kos.PvrListFinish()
        kos.PvrSceneFinish()
    }
}

This runs on a Dreamcast. Real hardware. 1998 technology. Go code.

Getting Started

Ready to begin? Head to the Installation page.

Or if you want to understand the full journey, start with Building From Nothing.